2 x Kidde Firex KF10 (4870) Mains Smoke Alarm Ionisation Sensor with 9V Built in Battery Back Up/Test and Hush Button

Order arrived very quickly, box slightly squashed in the mail but contents well packaged and solid enough. Easy to fit, neat little unit and all working flawlessly in less than 15 minutes. Obviously I haven't tested it by starting a fire but as far as I can tell all is good.

For a matched pair of ionisation type smoke detector/alarms, this purchase takes some beating on price, free delivery in 2 working days, and clear instructions for installation. My old alarms were ceiling mounted (ground and first floors) to a round spacious connection box with interface block for the mains cable(s) - see photo. All I had to do was replace the alarm wiring looms with the new ones provided and screw the new backing plates to the ceiling mount then attach and test the alarms complete with activated PP3 back-up batteries supplied. In the process, I discovered that the original house wiring was incorrect (in the photo, the grey (Signal) and black (Neutral) wires should have been the other way round). This meant that the old alarms never triggered each other as intended so, having fixed this, my home is safer than before and I am happy. Testing one alarm triggers the other after a few seconds, with slightly different pitch and in between beeps so I can differential between the two alarms. I suggest you check this when installing.Follow up report June 2020. One of the backing plates split around the screw holes and detached from the ceiling mount after a spell of really hot weather. I suspect the screws I used to fix the backing plate were a tight fit and the plastic weakened in the heat. I contacted the manufacturer and they sent me two new backing plates free. They were exceedingly helpful. I used smaller screws gently tightened just it case it happened again.

Purchased two detectors to replace date expired obsolete Kidde units. The connectors needed to be replaced but this was simple using a electrical connector block. Small gripes - the first connector mains warning tab on the connector snapped off as the connector was pushed on; second detector did not have any screw for fixing for the battery cover and the battery was hanging out. Both of these are not the suppliers fault but a manufacturing error as both units arrived in sealed boxes. Overall a very good price and quick delivery

These Firex Smoke Alarms are almost the identical to the 20 years old smoke alarms that they have now replaced.The recommended lifespan of these smoke alarms is 10 years so the old ones are an excellent guide to the reliability of this model. What was particularly good was that they fit directly on to the old base plates so I could fit them in approx 5 minutes each. Another plus point is that the green indicator LED is slightly larger and brighter than those of the old ones, so much easier to check.

Checked my smoke alarms and they are both out of their expiry date. Looked up on the internet and this is the direct replacement for the Firex 1240C detectors that I had.As such, really easy to install, both the base mount and the wiring/ connector are the same, but I changed the base anyway because the old ones have yellowed just like the detectors themselves. These have the same interconnect feature so when one goes off they both go off. My house isn't that big but it's good to have.Now the new ones look fresh on the ceiling and I'll sleep better knowing they will keep me & my family safe.

This is a well priced, easy to fit and pleasing to the eye set of wired smoke alarms. My only comment would be that the wiring clip that goes into the alarm could be a bit tighter, or hold better. Able to use original ceiling fixings, so no need for extra holes. Can't comment on battery life, as brand new. Had some issues wiring the upstairs alarm, but that was due to the original house wiring. Contacted manufacturer for assistance and they were most helpful. Quite speedy regular delivery. Would recommend this product and happily buy again.

I bought these to replace my old Kidde firex detectors.Naively I thought they lasted forever but actually they have a 10 year date on the smoke detection devices.My old ones lasted 18 years before they started to beep incessantly (even when disconnected and the battery removed!)I bought these as they were the up to date model of my previous ones.They actually did fit the mount and wiring of my old ones but I chose to change the mount due to discolouration and the wiring on one was change due to damage to the clip that locks the wire in place.They are easy to change over, just a couple of screwdrivers if you are placing them in the exact spot of previous ones.They look and perform as they should, I’m surprised how bright the green bulb is, it lights up the hallway, my previous ones could barely be seen!Reliable and long lasting they are a household must for smoke detection.

Initially disappointed as they seemed to be a little flimsy compared to replaced alarms. Since these weren't compatable with existing base-plates and I'm not a DIYer, I used an Electrician to install them. He had no difficulty fitting them and pronounced them to be OK in his opinion. Tested as fully operational but have yet to meet my wife's toast test. Expect them to work though. Also they look much smarter than our old ones.